1. Field of the Invention
The present invention relates to a method for dynamically determining the position of the stop point of an aircraft on a terrain, comprising the following steps:
dynamic measurement of the current geographical position of the aircraft, and its current ground speed;
calculation of a first length representative of a flight phase of the aircraft, and calculation of a second length representative of a ground phase of the aircraft;
calculation of the position of the stop point based on the first length, the second length and the current geographical position.
Such a method is intended to be implemented during the approach of the aircraft toward a terrain (for example, a landing strip) and during landing on that terrain.
The landing phase of an aircraft is a critical flight phase. In fact, during that phase, the pilot must manage to stop the aircraft on the runway, or must undertake a specific emergency procedure if he feels he will not be able to stop the aircraft before the end of the runway. The specific procedure is for example a go-around procedure if the speed of the airplane and the remaining length of the runway allow it.
2. Description of the Related Art
In this respect, statistical studies on aerial accidents having occurred in the last decade on commercial flights show that a majority of accidents take place during landing, and that the primary cause of approximately 18% of accidents is an exit of runway.
A significant share of these accidents are due, during the landing phase, to exit the length of runways. Several causes have been isolated for this type of accident, but in the majority of cases, the crew incorrectly estimated the ability to land the aircraft on the runway.
To offset this problem, systems and methods have been developed for allowing the pilot, during flight and/or on the ground, to estimate whether he will be able to land the aircraft in complete safety, and to estimate the braking capacities of the aircraft on the considered runway.
The estimate of the stop position of the airplane, presented to the crew during the approach and until the aircraft has come to a complete stop, is therefore information of great interest in terms of safety. This interest is even greater if the estimate accounts for the evolution of the system in real time.
In one known method, a minimal landing distance along the runway, until the aircraft is stopped, is calculated from the current position of the aircraft, from a standard descent plane toward the determined landing strip, and a performance model of the aircraft.
The calculation of the minimum landing distance comprises estimating a distance traveled above the runway during flight, based on the average flight time above the runway, and the estimate of a travel distance on the runway.
This method only considers the constant descent plane of the aircraft.
One aim of the invention is therefore to obtain a method for determining the stop point of an aircraft on the ground, which can be implemented during an approach phase and during rolling, and with improved precision.
To that end, the invention relates to a method of the aforementioned type, characterized in that the calculation of the first length comprises a phase for dynamically estimating a distance traveled by the aircraft during at least part of a flare phase of the aircraft.